AfriGeneas Slave Research Forum

Black and Mulatto were interchangeably used in the census records, depending on the year and location. It was at the discretion of the census taker of which he used, and many times it seems they used it to describe the coloring rather than a race, so keep that in mind.
Have you checked out FamilySearch Labs?

I found a couple of records for him there at the link below, and you can try different variations if you haven't done so yet, too.